Back packs are worn by travelers, students, hikers, etc., and are usually held in position by a pair of vertically oriented straps passing around the shoulders of the wearer. The free ends of each strap are usually joined together by a buckle, so that the length of each strap can be adjusted and the back pack rests comfortably upon the back of the wearer.
The back pack may contain valuable items, such as laptop computers and cameras, in addition to fresh clothing, worn clothing, toiletries, reading material, film, etc. At least one zipper, which may encircle the back pack in a horizontal, or vertical direction, is opened to provide access to the contents of the back pack. The zipper may be replaced by buttons, snaps, Velcro fasteners, etc., but the problem of unauthorized entry into the backpack remains unsolved.
Whereas the zipper provides access to authorized persons, including the wearer, the same zipper provides a readily accessible point of entry of thieves, pick pockets, and other unauthorized persons. The problem of unauthorized entry is exacerbated because the slider for the zipper is visible to persons walking behind the wearer, yet out of the view of the wearer, so that thieves, etc. may pilfer or damage the contents without being observed by the wearer of the back pack.
Diverse covers have been proposed for protecting a back pack, and its contents, from unauthorized entry. To illustrate, U.S. Pat. No. 5,154,352, granted Oct. 13, 1992, to C. W. Williamsen et al, discloses a fabric enclosure, or cover, 16 that accommodates back pack 58, as shown in FIG. 5. The cover is secured in place by straps 52 that pass around the shoulders of the wearer. Interlocking zippers 14a, 14b and 14c, can be interconnected by shackle 46, 48 as shown in FIG. 3A to prevent unauthorized opening of the enclosure to gain access to back pack 58.
U.S. Patent Application Publication 2005/0133558 discloses a multiple-use cover 20 with an easy opening zipper used to cover an article 10, such as a backpack. Zipper 23 and flap opening 30, allow the user to gain access to the contents of the backpack, without having to remove the cover from the pack, so that the wearer can pass quickly through inspection lines at an airport and other security check points.
U.S. Pat. No. 6,279,796, granted Aug. 28, 2001, to Jose Trevino, discloses a protective cover 10, with a drawstring 17 at its lower end, that allows the cover to be slipped over the back pack 2 to protect the back pack, and its contents, from damage from weather exposure.
Known protective devices, however, have proven to be largely ineffective in defeating unauthorized entry into back packs and tampering with the contents of the back pack.